We propose to further develop fast scan MR imaging and real-time image formation methods, as demonstrated in the previous grant cycle, for improved visualization of abdominal cancer. The proposed end-point is a single, integrated pulse sequence enabling completion of an MR abdominal exam in 12 minutes. We hypothesize that diagnostic quality Tl- and T2- weighted images superior in quality to conventional spin-echo images can be efficiently acquired-using breath hold scan times. Work will be done on three major projects: 1. Diagnostic Abdominal MR Image Acquisition. Diagnostic quality Tl- weighted and T2-weighted MR images will be acquired within breath hold scan times. Interleaved echo-planar and fast spin-echo methods will be used to form-high quality T2-weighted images. 2DFT magnetization-prepared gradient echo imaging will be refined to eliminate artifacts. Breath -hold feedback techniques will be used to provide precise registration of scanned sections from one acquisition to the next. Acquisition methods will be developed for imaging contiguous sections during successive registered breath-holds. 2. Interactive MR Imaging Techniques. The technique of breath-hold feedback will be developed and refined to enable reproducible (S/I diaphragmatic position within +/-1 mm) breathhold positioning. Methods will be developed for high speed positioning and calibration. 3. High Speed Image Reconstruction. The acquired diagnostic Tl- and T2- weighted images will be reconstructed immediately after acquisition with high speed hardware. Modifications will be made to accommodate the increased data rate and nonuniform response of multiple receiver coils. High speed image projection techniques will be developed to aid in the visualization of anatomy, pathology, and vasculature. 4. Integrated Pulse Sequence. The techniques developed in Projects 1, 2, and 3 will be integrated into a single sequence such that the complete exam time necessary to position the patient, perform calibration, and acquire and reconstruct high quality TI- and T2-weighted images of the liver is less than 12 minutes. Such times will improve the efficiency of the MR examination. Much of the proposed work addresses the deficiencies of modern MRI in breath hold imaging: deficiencies in the pulse sequences themselves, in accurate measurement and positioning of the degree of breath-holding, in rapid switching between sequences, and in image reconstruction.